| The experiments were carried out,in the sole-span plastic and multi-span plastic greenhouse in agriculture science and technology model garden(N31 51',E117 17';above the sea level 32.3m),suburb of HeiFei. Soil,fertilizer,management and cultivation etc were made at the same level. The characteristic weather and observational point were selected and then the instruments were installed to study the characteristic microclimate inside greenhouse. The microclimate data and the information of tomatoes inside were collected at the selected days. The experiments were originally designed with 6 treatments. They were:T,the treatment of covers with LS inside greenhouse;T2 the treatment of covers with LS outside the greenhouse;T3 the treatment of natural ventilation;T,the treatment of electric fan with wetted curtain;T,the heat treatment;T6 vegetables adaptation themselves. Every treatment was done 2 or 3 times in the same environment and the instruments were installed outside accordingly.The air temperature,soil temperature and the relative humidity and other characters were observed through the entire period of the experiments. The characteristic microclimate inside the greenhouse and the effects of the treatments were researched analyzed by means of Crops culture,Agricultural meteorology,physiology and Ecology,Agricultural statistics,Applied mathematics and so on. The results were significant to vegetables prodiv in the greenhouse.The main results as follows:1. the main characteristic microclimates inside greenhouse:the atmospheric temperature is much higher than outside,especially during the day while during night it changes slowly. The air temperature in the middle layer and the layer near the surface of the earth is much higher than the low layer and upper layer. The different type of weather influences the atmospheric temperature greatly. During the clear day,the air temperature is not even at all and if it is raining,the 6 is much small. And during the day,the air temperature is not even either:in the noon,the 6 is 1.54 while in the morning or in the afternoon it is relatively even and the 6<0. 5. The highest temperature is much higher and the lowest temperature is slightly higher than outside. And the soil temperature is high,too. The temperature of the surface of the earth changes much while the temperature below the surface of the earth changes less. The humidity is heavy and the light is less. And some equations were found between the temperature inside and outside greenhouse respectively. At last,the controlled equation about the temperature was studied.2. The basic theory of the main microclimate controlling measures of the greenhouse:(1) The theory to low the temperature by means of LS covered outside greenhouse is when the sun light radiates on the LS,some energy is sorbed,while some is reflected and all these happened outside greenhouse. And because the energy does not enter the greenhouse,so it dose not affect the temperature inside. (2) The theory to low the temperature by means of LS covered inside greenhouse is that the sun light transmits the surface of the greenhouse and reaches the LS and then some energy is reflected to the outside,some is sorbed by the LS to increase the temperature of the LS and then the air temperature inside. (3) the theory to low the temperature by means of electric fan with the wet curtain system is that the hot air is forced to go out and then the cold air comes in and it has to go through thewet curtain when the water vaporize,some energy is needed and so the temperature inside greenhouse becomes low. (4) The natural ventilation theory to low the temperature and humidity is that the cold and dry air comes in and the hot and humid air goes out. (5) The theory to increase the temperature inside by the heated machine is that when the fuel is ignited inside the machine then the heat is given out to heat the air inside greenhouse.3. effects when regulated:Effects to low the temperature as follows:Different measures to low the temperature inside are not the sam... |
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